smoking 2 stroke

I have a Kawasaki kh125 that is smoking slightly, the harder the
acceleration, the more smoke it kicks out! I am presuming that this is down
to the amount of 2 stroke oil that is being injected into the petrol/oil
mix. Does anyone know the procedure for altering this mix ratio?
All help greatly received.
Andy

 

In the days of old (in some two stroke cycle engines) this also could be
a leak from the transmission oil to the crankshaft chamber. Might
require some investigation before settling on one course of action
including what type of oil you're using.

 

Get a manual. It'll show the procedure for setting up the pump.
Generally, they have a little dot punched on the pump body or operating
lever, which corresponds with another dot or marker on the engine.

They should line up when the pump is fully open. Adjust the cable until
it does.

But all strokers smoke, and they'll smoke especially badly if they've
been pottered around and are then opened up.

Ride it hard for a while, and see if the smoke trail lessens.

As suggested, a seal leak is possible, allowing transmission oil into
the combustion chamber. Check the level of the transmission oil - it
should never fall. If it smells of petrol, this is a dead giveaway, but
generally, strokers with leaky seals tend to run badly, and if yours is
running OK, leave it alone.

Thrash the tits off it.

 

Assuming the bike has lived it's life so far un-altered in the oil mixture
area why would you want to severely shorten it's life expectancy by starving
the motor of oil?

 

dunno that type kwakker (on or off-road), so with the risk of being
considered quite stupid: is it premix or separate reservoirs?
If you use premix, bring the rate down a bit (less oil). In pumped mix,
dunno either ;-)

anyway, if it's way too blue, consider a top-endie

Pepe (00 Ducati M900 bella nera - 76 Honda CB350 cappuccino-style - 82
Kawasaki KDX175 green laner)
Visit www.motor-europe.com

 

Instead of trying to alter your fuel/oil mix(32:1 ratio should be
about correct for a 125) more likely you need a top end(rings).
If the rings don't have many hrs on them then look to other areas.
1)Has it always had this much smoke?
2)Has the weather changed?

Learn to adjust your carb settings to match weather conditions
especially on a 2 stroke. Jetting is fundamental. Don't starve your
lower end bearings of oil lubrication.
philb

 

The "top end" has nothing whatsoever to do with the amount of smoke
coming out of the exhaust pipe on a two stroke engin!

The problem is most probably one of three things:
1 )The the oil pump half of the throttle cable outer housing may be
pulled out of place causing the pump to pmup way too much.
2) The oil being used my be unsuitable.
3) The smoke produced may be "normal". The original post says the bike
is "smoking slightly". This sounds like a very good description of a
kh125 that has no problem with the oil injection rate or oil!

What are you talking about? The original poster is concerned about a
kh125 engine producing excess smoke. Carb jetting on this bike is
adjusted according to performance (blubber or bogg) and plug readings,
not by monitoring smoke output.

 

Eh? It depends entirely on the quality of two-stroke oil. Use quality
fully synthetic and 50:1 is fine.

This is a *two-stroke*, you fool.

Oh, please don't talk such utter, utter crap.

True. At last.

True again.

 

There are many useful tech articles on the web.
This one has helped me to understand the basics and to dial in my
finicky KTM.

http://www.all-offroad.com/DirtBikes/Beginners/BGNov98.html

Carb jetting is probably the biggest culprit to poorly running motors,
yet can be easily fixed with basic tools and some time.
Also check your air filter. A dirty filter will make the bike rich(too
much fuel, not enough air in the mix)which will make it smoke.
Hope this helps.
philb

 

From all your postings so far it's taught you *nothing*.

Yes, but excessive smoke from a two-stroke has eff-all to do with this.

Jesus H. Christ. wheoever said "A litle learning is a dangerous thing"
is correct. Yes, a clogged air filter will make an engine smoke but it
will be *black* smoke from excessive fuel and, once again, *nothing* to
do with what his problem (if it exists, which I really doubt).

It doesn't and it won't.

 

if the rings are worn---the motor does have rings--- dickhead, then
oil will blowby. when oil burns it smokes. ultimately out the end of
the exhaust pipe.

I agree.

What is unsuitable? Hopefully the owner of the bike knows the
difference bewtween 2 cycle oil and 90wt. gear oil. Yamalube 2s
injector oil is very good as are most motorcycle specific injection
type oils.I personally would try what the motorcyle manufacturer
recommends in the manual.

Agreed.
The original post also says that it gets worse as the throttle is
opened.

I dunno about what your experience with 2 stroke motors is so I will
refrain from attacking you but from my personal experience I can get
my KTM 300 to smoke or not smoke just by changing a needle clip
position. Excess smoke comes from too much fuel vs. air mixture at the
carb. The bike is an injector type from what I understand,so likely
the injection unit is not calibrated incorrectly(assuming that no one
has touched it or cables misconnected as you already spoke about. I
would hate to see an adjustment made to decrease the volume of oil and
then have the piston melt or the lower end bearings seize.



Carb jetting on this bike is

Smoke output is also a measure of performance. too much suggests
incorrect carb settings. Or it needs new rings.Or the air filter
cleaned.

 

The oil is mixed with the petrol. It burns in the combustion chamber.

It doesn't just "blow by" all by itself. There is no separate
lubrication system on a two-stroke, barring the oil bath that the
gearbox sits in.

 

Agreed. What's your point? 32:1 is also perfectly fine.
Most likely the injection unit on the bike is set somewhere in these
ranges. Eh..?

As opposed to what? And please do not call me a fool.

Humidity and elevation don't affect carb settings?

Whew... I thought I was going to get and "F" in red pen.

So why would anyone try to decrease the amount of oil in the mix to
compensate for other issues?

 

I think you should understand the different lubrication systems employed
by two-stroke and four-stroke engines.

Worn rings will not really make a two-stroke noticeably smokier. And,
since I notice you've dodged this issue, an over-rich mixture won't make
it smokier either (unless it's so rich you get black smoke).

Very few two-strokes have oil control rings like a four-stroke does, and
a Kawasaki KH125 certainly doesn't.

To tackle your assertion that weather doesn't alter carb settings - of
course it does, but to a tiny degree, and road bikes certainly don't
need carb jet changes whenever the sun goes behind a cloud. A race bike,
tuned to the nth degree, is a different matter, of course. If you are
seriously suggesting he should alter his carb settings when the weather
changes, you are an idiot.

Now, to deal with your abusive email, which I quote below for the
benefit of all and sundry:

STARTS/
Hey what is up with you? If I am wrong in my thinking and advise perhaps
someone with your obviously greater knowledge could straighten me out. I
don't believe that I am an asshole... why should you?
I don't think that I ever challenged anyone here. But jump on
me...without
cause other than different technical opinions on a vague symptoms of
engine
trouble.
Who is the asshole?
Not me.
/ENDS

You have a little knowledge, but not enough to stop you making yourself
out to be a fool on this issue.

 

The "top end" has nothing whatsoever to do with the amount of smoke

It appears that you do not have an understanding of the difference
between a 2-stroke and a 4-stroke motor! Worn rings will NOT
contribute to oil burning and smoking on a 2-stroke engine.

Where do you think the oil goes that a 2-stroke engine uses, whether
it be oil injected or premixed in the gas tank? It all ultimately goes
into the combustion chamber, then out the exhaust. If it did not, it
would have to accumulate somewhere. Where would that be?

Incidentally, how did you know my nickname? Only my family and close
friends call me Dickhead!

Dickhead

 

I've tried telling him this, but because of his vast knowledge, gleaned
from "many useful tech articles on the web", he thinks he knows better.

Hello, philb, this is your starter question for one dollar....

 

Hey it's not the 1st time I 've stepped in a puddle. You are correct.

Wow! Elevated to "family"! and we only just met!

 

Reducing the amount of oil by thinning out your mix ratio actually
lowers opporating temperatures. Typically, anything you can get to
run cooler will last longer as a generic rule of thumb. Oil burns
hot, i.e. oil burning furnace. A thinner mix ratio can be achieved
with a good synthetic which has a high film strength.

http://www.synthetic-solutions.com/2cycle.htm

I have a question. I work within the moto x arena and have come
across two different perspectives. Some people think that going from
50:1 to 100:1 is actually a richer mix ration because they look at it
like the bike is burning more gas so therefore it is a richer mix
ration of gas to oil. Any input?

David-

 

Heh. I think in the UK we had the opposite problem - people didn't
know they had oil injection and ran the bikes until the oil tank
emptied, with predictable results.

 

LOL.....this is a great thread.

FVH (feeling very humble)
I am definitely glad you stepped in to straighten us out Hank. May I
ASSUME that you will help us out if we again get off track, since our
knowledge is so limited?

Dickhead